Typical semiautomatic pistols are equipped with moveable barrels which are locked into moveable slides during firing. The required clearances between the interfacing moveable parts and the motion of the parts during firing contributes to reduction in accuracy of the weapon. The required number of parts and the inherently complex machining of the parts of conventional pistols contributes to high cost of finished weapons. The M1911 series of U.S. service pistols and other pistols based upon the Browning operating system is the most common high powered semiautomatic pistol design in the world. The relative motion of the barrel with the frame in these weapons requires careful gunsmithing in order for these pistols to shoot accurately.
The present invention provides for more accurate fire and for lower cost manufacture for semiautomatic pistols and other short barreled weapons firing high powered cartridges. Unlike typical medium and high powered semiautomatic pistols, the barrel of the present invention is fixed to the frame of the weapon, eliminating movement of the barrel relative to the frame.
The invention can be applied as a modification to existing weapons permitting the owner of an existing weapon to significantly improve the performance of the weapon by replacing the appropriate parts with the present invention.
The present invention eliminates the typical barrel link and link pin from conventional weapons which have been modified with the present invention. When applied to new-manufacture weapons, in addition to eliminating the barrel link and link pin, the machining of locking lugs on the barrel and of the locking recesses in the slide are eliminated.
The present invention utilizes a portion of the gases generated during firing in order to retard the rearward movement of the recoiling parts. Gas is vented through a hole just forward of the chamber into a gas cylinder below, and parallel to the barrel. The barrel and gas cylinder are a unit which is fixed to the frame of the weapon. The gas cylinder is closed at the rear and open at the front. A close fitting piston fits the gas cylinder. The forward end of the piston, through intervening parts, bears against the operating slide. The gas piston is provided with a self centering means which permits the piston to be machined to a close fit with the gas cylinder in spite of possible imperfect alignment of other related parts.
When the weapon is fired, the propellant gases drive the projectile forward and drive the cartridge case and slide rearward. During initial movement of the projectile, and until the projectile base reaches the gas port just forward of the chamber, the weapon operates as a simple blowback weapon. As the base of the projectile passes the gas port, the gas port is exposed to the same high pressure gases which are driving the projectile. Gas is vented through the gas port and into the volume defined by the gas cylinder and gas piston. The gas in the cylinder applies force against the piston which retards rearward movement of the slide.